Articulated Operating Arm and Mobile Apparatus with Improved Mounting of Control Member

ABSTRACT

Articulated operating arm including at least a first articulation and a second articulation, which first articulation is connected for pivoting around a first axis to the second articulation. A control member is operative for the purpose of moving the second articulation relative to the first articulation, which control member has a first end coupled to a coupling structure which is configured to connect this first end for pivoting around a second axis to the second articulation, which second axis is parallel to the first axis. The second articulation includes an elongate structure and a wing; which elongate structure has a first end for connection to the first articulation, a second end and a side wall between the first and the second end; which wing is attached to the elongate structure. The coupling structure has a first end supported at the side wall and a second end supported by the wing.

FIELD OF THE INVENTION

The present invention relates to the field of articulated operating arms with at least two articulations, in particular with at least three articulations and still more particularly with folding articulations, and of mobile apparatuses with such an operating arm, such as for instance construction machines for excavating and loading shovel operations, agricultural machines such as tractors, forestry machines with wheels or caterpillar tracks, or other displacing means with a fixed frame or with a rotatable sub-frame on a main frame.

BACKGROUND

Known mobile apparatuses are described in, among others, the patent specifications NL2004954, NL2004784, NL2002125, NL1035694, NL1028661, NL1027370 and NL1019918 in the name of Applicant. The text of these patents is included here by way of reference.

SUMMARY OF THE INVENTION

Embodiments of the invention have the object of providing an improved articulated operating arm and mobile apparatus, and in particular an articulated arm with at least two articulations and a control member which allows a better distribution of forces in the articulations.

A first aspect of the invention relates to an articulated operating arm for a mobile apparatus comprising at least two articulations and a control member. The at least two articulations comprise a first articulation and a second articulation. The first articulation is connected for pivoting around a first axis to the second articulation, wherein the control member is operative for the purpose of moving the second articulation relative to the first articulation. The control member has a first end coupled to a coupling structure which is configured to connect this first end for pivoting around a second axis to the second articulation. The second axis is parallel to the first axis. The second articulation comprises an elongate structure and a wing. The elongate structure has a first end for connection to the first articulation, a second end and a side wall between the first and the second end. The wing is attached to the elongate structure. The coupling structure has a first end which is supported at the side wall of the elongate structure and a second end which is supported by the wing.

A better distribution of forces is obtained by holding the first end of the control member fixedly with a coupling structure which is supported on the one hand by the elongate structure and on the other by the wing, particularly in an embodiment in which the first articulation can be folded to a position against the second articulation by the control member. Embodiments of the invention after all allow the control member, as seen in top view, to be provided adjacently of the elongate structure without appreciable loss of strength. Owing to the suspension at two ends of the coupling structure there is less fatigue in the material of the control member and in the coupling structure which holds the control member, particularly in a folding arm which can be transformed from an articulated state to a single lifting arm state for the purpose of lifting loads or coupling of implements in both modes.

The control member is preferably operative between the first and the second articulation and is for instance a piston-cylinder assembly.

The elongate structure preferably comprises a hollow tube. Such a tube can impart the necessary strength to the articulation without making it heavy.

The wing preferably has a first long side with an elongate portion attached to an upper side of the elongate structure, and a second free long side. This free long side is preferably shaped such that the forces can on the one hand be properly absorbed and that the control member is on the other protected against fouling. The elongate portion on the first long side of the wing preferably forms a part of an upper side of the hollow tube. The wing is preferably formed so as to extend at least partially over the coupling structure. The wing is preferably plate-like. The wing preferably has a width in a direction transversely of the elongate structure which is greater at the first end of the elongate structure than at the second end of the elongate structure. The wing has for instance a first portion of a constant width adjacently of the first end of the elongate structure, after which the wing becomes gradually shorter in the direction of the second end of the elongate structure.

In an advantageous embodiment the second articulation comprises a connecting plate for connecting the second end of the coupling structure to the wing. This connecting plate thus forms a suspension for the second end of the coupling structure from the wing.

Preferably attached to the first end of the elongate structure is an extension piece which is oriented transversely of the elongate structure, the extension piece being attached to the wing. The extension piece transmits the force to a shaft pivotally connecting the first and second articulations so that the forces from the control member are better distributed over the two articulations between which the control member operates. In preferred embodiments this is brought about by the flowing lines of the free long side of the wing from the first end of the second articulation to the second end of the second articulation. In addition to having a structural function, the extension piece with wing also has a protective function in the folded-up state because it can protect technical parts of the mobile apparatus, and particularly also the control member and other parts of the articulations, from the surface, the soil, the sand, the stones etc. over which the mobile apparatus travels.

In an advantageous embodiment the coupling structure comprises a pin, and the first end of the control member is formed as a hollow shaft through which the pin protrudes. The pin then preferably protrudes through an opening in the connecting plate. According to a variant, the coupling structure comprises one or more hollow shaft parts, and the first end of the control member is formed as a solid shaft which is receivable in the one or more hollow shaft parts. A first such hollow shaft part can then be attached in the connecting plate and a second in the side wall.

The control member is preferably configured to move the second articulation to a position against or adjacently of the first articulation, wherein in the folded-up position of the articulated operating arm the wing extends partially over the control member in order to protect this control member.

In the preferred embodiment the at least two articulations comprise a third articulation and the second articulation is connected for pivoting around a third axis to the third articulation, wherein a further control member is provided for the purpose of moving the third articulation relative to the second articulation, wherein the further control member is connected for pivoting around a fourth axis to the second articulation, this fourth axis being parallel to the third axis. The further control member is preferably connected to the elongate structure at the first end of the elongate structure and on the upper side thereof. The elongate structure is then preferably provided with an elongate recess provided adjacently of the wing and configured to partially receive the further control member. The skilled person will appreciate that it is also possible to provide the further control member on the underside, in which case a recess can be provided on the underside. The further control member is preferably configured to move the third articulation to a position against or adjacently of the second articulation, this such that the articulated operating arm can be transformed into a single lifting arm, see also the above cited earlier patents in the name of Applicant which are included here by way of reference.

In a possible embodiment the second articulation comprises a first hollow shaft part attached to the first end of the elongate structure, which first hollow shaft part is configured to realize the pivoting connection around the first axis between the preceding and the second articulation. The second articulation can further comprise a second hollow shaft part which is attached to the extension piece, which second hollow shaft part lies in line with the first hollow shaft part, wherein a shaft part is received in the first and the second hollow shaft parts for the purpose of realizing the pivoting connection around the first axis between the first and the second articulation. The second hollow shaft part is preferably fixed against the extension piece by means of bolts.

The shaft part is preferably fixed relative to the first articulation by means of a fixed connection, preferably a keyway.

In a further developed embodiment the elongate structure is a hollow tube which is provided on the inner side with reinforcements formed by additional material and/or plates which further transmit the forces acting on the pivoting connection between the first and second articulations into the second articulation, preferably over the full width of the hollow tube.

In a still further developed embodiment the hollow tube is provided on its second end with a solid coupling piece welded against this second end, and the hollow tube is provided on its second end with reinforcements formed by additional material and/or plates which transmit the forces between the second articulation and the third articulation at the position of the coupling piece which is pivotally connected to the third articulation.

Other embodiments of the invention have the object of providing an improved articulated operating arm and mobile apparatus, and in particular an articulated arm with at least two articulations and a control member which allows guiding of a conduit from a first articulation of the operating arm to a second articulation without appreciable loss in respect of freedom of movement of the articulations.

Provided according to a second aspect of the invention is an articulated operating arm for a mobile apparatus comprising at least two articulations and a control member. The at least two articulations comprise a first articulation and a second articulation. The first articulation is connected for pivoting around a first axis to the second articulation, wherein the control member is operative for the purpose of moving the second articulation relative to the first articulation. At least one conduit runs in the form of a loop from the first articulation to the second articulation. The loop is dimensioned such that it can become smaller or larger when the second articulation is moved respectively in the direction of the first articulation or away from the first articulation.

The first articulation is preferably connected pivotally to the second articulation by means of a hollow shaft part, and the at least one conduit preferably runs from a side wall of the first articulation through the hollow shaft part to the second articulation. A conduit can in this way be carried in a convenient manner from a first side wall of a first articulation to another side wall of a subsequent articulation, this being particularly useful in articulated operating arms with several articulations, and in particular foldable articulated operating arms.

The at least one conduit is preferably attached to the first articulation and to the second articulation close to the first axis (A1). These locations are preferably chosen such that the movement of the conduits during rotation of the second articulation relative to the first articulation affects only the size of the loop. The at least one conduit is preferably attached against a side wall of the second articulation.

The at least one conduit can comprise a first and a second conduit which, as seen in a top view of the first and second articulations, are positioned adjacently of each other and each run in a loop of substantially the same radius from the first articulation to the second. The at least one conduit can also comprise a first and a second conduit which, as seen in a top view of the first and second articulations, are positioned one below the other and each run in a loop with a different radius from the first articulation to the second. Combinations hereof are also possible. The radius of the loop can further be adapted to the dimensions of the diameter of the conduit and/or to the stiffness of the conduit.

The at least one conduit typically comprises one or more of the following: a conduit configured to transport a liquid or gas under pressure; an electrical cable.

The control member is preferably configured to move the second articulation to a position against or adjacently of the first articulation. In a preferred embodiment the at least two articulations comprise a third articulation, and the second articulation is connected for pivoting around a third axis to the third articulation. A further control member can then be provided for the purpose of moving the third articulation relative to the second articulation, wherein the further control member is connected for pivoting around a fourth axis to the second articulation, this fourth axis being parallel to the third axis.

Advantageous embodiments are described in the dependent claims.

Note that the claims describe a structure with one wing, but that the skilled person will appreciate that such a wing construction can be provided on both sides of the second articulation.

BRIEF DESCRIPTION OF THE FIGURES

The above and other advantageous features and objectives of the invention will become more apparent and the invention better understood with reference to the following detailed description when read in combination with the accompanying drawings, in which:

FIG. 1 illustrates a perspective view of a first embodiment of an operating arm according to the invention;

FIG. 2 shows a perspective detail view of a part of the operating arm of FIG. 1 as seen from below;

FIG. 3 shows a first perspective view of the second articulation of the operating arm of FIG. 1 when looking at a side wall thereof;

FIG. 4 shows a second perspective view of the second articulation of the operating arm of FIG. 1 when looking at a first end thereof intended for connection to the first articulation;

FIG. 5 shows a first perspective view of the operating arm of FIG. 1 in the folded-up position when looking at the underside thereof;

FIG. 6 shows a second perspective view of the operating arm of FIG. 1 in the folded-up position when looking at the upper side thereof;

FIG. 7 illustrates a mobile apparatus according to the invention;

FIG. 8 illustrates a second embodiment of an operating arm according to the invention;

FIG. 8A shows a schematic top view of the first and the second articulation of the second embodiment of FIG. 8;

FIG. 9 illustrates the operating arm of FIG. 8 in a partially folded-up position;

FIG. 10 illustrates the operating arm of FIG. 9 in a fully folded-up position.

DETAILED EMBODIMENTS

A first embodiment of an operating arm according to the invention is illustrated in FIGS. 1-6. This is an articulated working arm for a mobile apparatus with three articulations 1, 2, 3 and with a number of control members 6, 7, 8 and 9. A first articulation 1 is intended for connection to a main frame of a mobile apparatus and is movable by the control member 8 intended to be operative between the main frame and first articulation 1. A second articulation 2 is connected for pivoting around a first axis A1 to first articulation 1, wherein control member 6 is operative for the purpose of moving second articulation 2 relative to first articulation 1. Second articulation 2 is connected for pivoting around third axis A3 to third articulation 3, and control member 7 is provided for the purpose of moving third articulation 3 relative to second articulation 2. Finally, control member 8 is intended for the purpose of controlling an implement connected to the third articulation. The skilled person will appreciate that the operating arm can be provided with more than three articulations, and that more or fewer control members are possible depending on the desired function of the operating arm.

Control member 6 has a first end 601 which is coupled to a coupling structure, here in the form of a pin 210 configured to connect this first end 601 for pivoting around a second axis A2 to second articulation 2. The second axis A2 is parallel to the first axis A1. The first end 601 of control member 6 is provided with a hollow shaft part 610 through which pin 210 protrudes, see FIG. 2. Note that the pin is not shown in FIG. 1. In the illustrated embodiment the control member 6 is a piston-cylinder assembly 620, 630 and the first end is an outer end of a piston rod 620 on which a hollow shaft part 610 is provided. According to a variant, the outer end of piston rod 620 could be provided with a solid shaft part instead of a hollow shaft part 610, and two hollow shaft parts in which the solid shaft part is receivable could be provided as coupling structure instead of a pin 210.

As shown best in FIG. 3, the second articulation comprises an elongate structure, here in the form of a hollow tube 220; a wing 230; an extension piece 280; and a connecting plate 240. The hollow tube 220 has a first end 221 for connection to the first articulation, a second end 222 for connection to the third articulation and a side wall 223 between the first and the second end, see FIG. 4. Wing 230 is attached to hollow tube 220. Wing 230 has a first long side 231 with an elongate portion attached to an upper side of hollow tube 220, and a second free long side 232 which extends partially over pin 210. The elongate portion on the first long side 231 of wing 230 here forms a part of the upper side of hollow tube 220. Wing 230 has a width in a direction transversely of hollow tube 220 which is greater at the first end 221 of hollow tube 220, see width b1 in FIG. 3, than at the second end 222 of hollow tube 220, see width b2. The wing further has on at least a part of its free long side 232 a flowing line which ensures that the width decreases gradually in the direction of second end 222 of hollow tube 220 so as to bring about a good distribution of forces.

Pin 210 has a first end 212 which is supported at side wall 223 of hollow tube 220 and a second end 211 which is supported via connecting plate 240 by extension piece 280 and wing 230. Side wall 223 can for instance be provided with a pin receiving part, for instance a hollow shaft part, in which the first end 212 of pin 210 is supported. Connecting plate 240 is attached to wing 230 and extension piece 280, and pin 210 protrudes through an opening 241 in connecting plate 240. The pin can be provided at its end 211 with a head part 213 which is fixed against connecting plate 240, although the skilled person will appreciate that this is not essential and that other ways of blocking the pin 210 can be envisaged. Note that pin 210 can also be bearing-mounted at its outer ends 211 and 212 and need not be fixedly attached.

As shown best in FIG. 3, extension piece 280 is provided at the first end 221 of hollow tube 220 and oriented transversely of hollow tube 220. This extension piece 280 is further attached against an underside of wing 230. In the illustrated variant the wing 230 extends downward to a position behind extension piece 280, see also FIG. 4.

Second articulation 2 further comprises a first hollow shaft part 250 which is attached to the first end 221 of hollow tube 220. The first hollow shaft part is configured to realize the pivoting connection around first axis A1 between first articulation 1 and second articulation 2, see FIG. 4. Further provided is a second hollow shaft part 260 which is attached to extension piece 280, see also FIG. 3 where the second hollow shaft part 260 is not drawn but where the outer end of the transverse extension piece 280 is shown against which the second hollow shaft part 260 is attachable by means of bolts (not shown). The second hollow shaft part 260 lies in line with the first hollow shaft part 250 so that a shaft part 110 (see FIG. 4) is receivable in the first and the second hollow shaft part 250, 260 for the purpose of realizing the pivoting connection around the first axis A1 between the first and the second articulation. Shaft part 110 can be fixed to first articulation 1 or to second articulation 2. In the illustrated variant the end 120 of first articulation 1 is provided with a continuous opening for shaft part 110. Further provided in this end 120 is an opening 130 in which a key is receivable in order to fix shaft part 110 relative to the first articulation. According to an alternative embodiment, shaft part 110 could be fixed relative to the first articulation, for instance by means of a key through hollow shaft part 250.

Second articulation 2 is connected for pivoting around third axis A3 to third articulation 3, and control member 7 is provided for the purpose of moving third articulation 3 relative to second articulation 2, wherein at the first end of hollow tube 220 control member 7 is connected for pivoting around a fourth axis A4 to second articulation 2, this fourth axis A4 being parallel to the third axis. Hollow tube 220 is provided with an elongate recess 270 which extends adjacently of wing 230 and is configured to partially receive control member 7. This will allow compact and proper folding-up of the articulated arm.

Hollow tube 220 can be provided on the inner side with reinforcements formed by additional material and/or plates which further transmit the forces acting on the pivoting connection between first articulation 1 and second articulation 2 into second articulation 2, preferably over the full width of hollow tube 220. Hollow tube 220 is further provided on its second end 222 with a solid coupling piece 290 which is welded against this second end 222. Hollow tube 220 can then be provided at its second end 222 with reinforcements formed by additional material and/or plates which transmit the forces between second articulation 2 and third articulation 3 at the position of coupling piece 290 which is connected pivotally to third articulation 3.

FIGS. 5 and 6 show that the operating arm of FIG. 1 can be folded up by operating control members 6, 7 and 8. As best shown in FIG. 5, wing 230 extends partially over control member 8 in the folded-up position. Extension piece 280 preferably has, as seen in the folded-up—single—lifting arm position, a wide form such that in the lower lifting arm position it protects parts of the arm lying above or a control member.

Embodiments of the invention have, among others, one or more of the following advantages relative to the prior art:

-   -   a better distribution of forces for holding the outer end of a         control member in a foldable arm;     -   owing to the suspension from two ends of the coupling structure         there is less fatigue in the material of the control member and         in the coupling structure holding the control member,         particularly in a foldable arm which can be transformed from an         articulated state to a single lifting arm state for the purpose         of lifting loads or coupling implements in both modes;     -   the wing which holds the coupling structure is preferably fixed         to an extension piece, this extension piece transmitting the         force to a shaft pivotally connecting a first and second         articulation so that the forces from the control member are         better distributed over the two articulations between which the         control member acts; this is also brought about by the flowing         lines of the free long side of the wing from the first end of         the second articulation to the second end of the second         articulation;     -   in addition to a structural function, the extension piece with         wing also has a protective function in the folded-up state         because it can protect technical parts of the mobile apparatus,         and particularly also the control member and other parts of the         articulations, from the surface, the soil, the sand, the stones         etc. over which the mobile apparatus travels;     -   the extension piece and the wing mounted on the extension piece         which are connected to the shaft between the first and the         second articulation enable a proper mounting. The wing can be         secured with mounting means such as for instance bolts.

FIG. 7 illustrates a mobile apparatus with an articulated operating arm in the folded-up position (see FIGS. 5 and 6). The mobile apparatus comprises a main frame 710 displaceable on displacing means, here wheels 730, and a sub-frame 720 connected rotatably to the main frame. The articulated operating arm with articulations 1, 2, 3 is connected to main frame 710.

FIGS. 8-10 illustrate a second embodiment of an articulated operating arm for a mobile apparatus which has a construction largely similar to that of the operating arm according to the first embodiment and in which the same reference numerals are used to refer to similar components. The articulated arm comprises a first and a second articulation 1, 2 and a control member 6. The first articulation is connected for pivoting around a first axis (A1) to second articulation 2, wherein control member 6 is operative for the purpose of moving second articulation 2 relative to first articulation 1. Three conduits 200 run in the form of a loop L from first articulation 1 to second articulation 2, the loop L being dimensioned such that it can become smaller or larger when second articulation 2 is moved respectively in the direction of first articulation 1 or away from first articulation 1. The loop is thus dimensioned such that it allows a limited rotation of second articulation 2 relative to first articulation 1. This limited rotation is preferably sufficient to move the second articulation to a position against or adjacently of first articulation 1.

First articulation 1 is connected pivotally to second articulation 2 by means of a hollow shaft part 100 (which functions similarly to shaft part 110 of the first embodiment), and the three conduits run from a side wall of first articulation 1 through hollow shaft part 100 to a side wall of second articulation 2, see also FIG. 8A. In such an embodiment the conduits therefore run on the right along the first articulation and on the left along the second articulation, or vice versa. Conduits 200 are preferably attached to the first articulation and to the second articulation close to first axis A1, see attachment points 202 and 203 in FIG. 8A.

In the illustrated variant the three conduits 200 are positioned one below another as seen in a top view of the first and second articulations 1, 2 and they each run in a loop L with a different radius from the first articulation to the second. It is however also possible to provide a plurality of conduits which, as seen in a top view of the first and second articulations, are positioned adjacently of each other and each run in a loop of substantially the same radius from the first articulation to the second.

Conduit 200 can comprise one or more of the following: a conduit configured to transport a liquid or gas under pressure; an electrical cable.

There are no solutions available in the prior art which allow the possibility of conduits folding/rotating more than 120 degrees in a very compact space as will typically be the case in embodiments of the invention. Applicant previously devised a solution with a swivel joint, which solution is readily possible for hydraulic fluid although it entails a pressure drop due to the resistance in the swivel joint. The embodiments of FIGS. 8-10 provide a good alternative to the swivel joint and have the advantage of being a cheaper solution.

The skilled person will appreciate that embodiments of the invention can also be readily applied in operating arms with two articulations or in operating arms with more than two articulations. The structure of the second articulation can thus also be applied for instance in a third, fourth or fifth articulation of an arm with five articulations.

It is further possible to provide the wing and extension construction on either side of second articulation 2, i.e. a left and a right-hand wing 230, a left and a right-hand extension piece 280 etc., wherein a left and a right-hand control member 6 can then be provided.

An articulated operating arm as described above can be applied in, among others, construction machines for excavating and loading shovel operations, in agricultural machines such as tractors, in forestry machines with wheels or caterpillar tracks, or other displacing means with a fixed frame or with a rotatable sub-frame on a main frame. Such machines are described in the patent specifications NL2004954, NL2004784, NL2002125, NL1035694, NL1028661, NL1027370 and NL1019918 in the name of Applicant, and the text of these patents is included here by way of reference.

The skilled person will appreciate that the invention is not limited to the above described embodiments and that many modifications and variants are possible within the scope of the invention, which is defined solely by the following claims. 

1. An articulated operating arm for a mobile apparatus, comprising at least two articulations and a control member; wherein the at least two articulations comprise a first articulation and a second articulation, which first articulation is connected for pivoting around a first axis to the second articulation, wherein the control member is operative for the purpose of moving the second articulation relative to the first articulation, which control member has a first end coupled to a coupling structure which is configured to connect the first end for pivoting around a second axis to the second articulation, which second axis is parallel to the first axis, wherein the second articulation comprises an elongate structure and a wing; which elongate structure has a first end for connection to the first articulation, a second end and a side wall between the first and the second end; which wing is attached to the elongate structure, and that the coupling structure has a first end which is supported at the side wall of the elongate structure and a second end which is supported by the wing.
 2. The articulated operating arm as claimed in claim 1, wherein the elongate structure comprises a hollow tube.
 3. The articulated operating arm as claimed in claim 1, wherein the wing has a first long side with an elongate portion attached to an upper side of the elongate structure, and a second free long side.
 4. The articulated operating arm as claimed in claim 3, wherein the elongate portion on the first long side of the wing forms a part of an upper side of a hollow tube.
 5. The articulated operating arm as claimed claim 1, wherein the wing is formed so as to extend at least partially over the coupling structure.
 6. The articulated operating arm as claimed in claim 1, wherein the second articulation comprises a connecting plate for connecting the second end of the coupling structure to the wing.
 7. The articulated operating arm as claimed in claim 1, wherein an extension piece oriented transversely of the elongate structure provided on the first end of the elongate structure, the extension piece being attached to the wing.
 8. The articulated operating arm as claimed in claim 1, wherein the wing has a width in a direction transversely of the elongate structure which is greater at the first end of the elongate structure than at the second end of the elongate structure.
 9. The articulated operating arm as claimed in claim 1, wherein the coupling structure comprises a pin, and that the first end of the control member is formed as a hollow shaft through which the pin protrudes.
 10. The articulated operating arm as claimed in claim 9, wherein the pin protrudes through an opening in the connecting plate.
 11. The articulated operating arm as claimed in claim 1, wherein the control member is configured to move the second articulation to a position against or adjacently of the first articulation, and that in the folded-up position of the articulated operating arm the wing extends partially over the control member in order to protect the control member.
 12. The articulated operating arm as claimed in claim 1, wherein the at least two articulations comprise a third articulation and that the second articulation is connected for pivoting around a third axis to the third articulation, and that a further control member is provided for the purpose of moving the third articulation relative to the second articulation, wherein at the first end of the elongate structure the further control member is connected for pivoting around a fourth axis to the second articulation, this fourth axis being parallel to the third axis, wherein the elongate structure is provided with an elongate recess provided adjacently of the wing and configured to partially receive the further control member.
 13. (canceled)
 14. The articulated operating arm as claimed in claim 12, wherein the further control member is configured to move the third articulation to a position against or adjacently of the second articulation, this-such that the articulated operating arm can be transformed into a single lifting arm.
 15. The articulated operating arm as claimed in claim 1, wherein the second articulation comprises a first hollow shaft part attached to the first end of the elongate structure, which first hollow shaft part is configured to realize the pivoting connection around the first axis between the preceding and the second articulation, and wherein the second articulation comprises a second hollow shaft part which is attached to the extension piece, which second hollow shaft part lies in line with the first hollow shaft part, wherein a shaft part is received in the first and the second hollow shaft parts for the purpose of realizing the pivoting connection around the first axis between the first and the second articulation.
 16. (canceled)
 17. (canceled)
 18. (canceled)
 19. The articulated operating arm as claimed in claim 1, wherein the elongate structure is a hollow tube which is provided on the inner side with reinforcements formed by additional material and/or plates which further transmit the forces acting on the pivoting connection between the first and second articulations into the second articulation.
 20. (canceled)
 21. (canceled)
 22. (canceled)
 23. A mobile apparatus comprising an articulated operating arm as claimed in claim 1, wherein the mobile apparatus comprises a main frame displaceable on displacing means and a sub-frame connected rotatably to the main frame, and that the articulated operating arm is connected to the main frame.
 24. (canceled)
 25. An articulated operating arm for a mobile apparatus, comprising at least two articulations and a control member; wherein the at least two articulations comprise a first articulation and a second articulation, which first articulation is connected for pivoting around a first axis to the second articulation, wherein the control member is operative for the purpose of moving the second articulation relative to the first articulation, wherein at least one conduit runs in the form of a loop from the first articulation to the second articulation, which loop is dimensioned such that it can become smaller or larger when the second articulation is moved respectively in the direction of the first articulation or away from the first articulation.
 26. The articulated operating arm as claimed in claim 25, wherein the first articulation is connected pivotally to the second articulation by means of a hollow shaft part, and that the at least one conduit runs from a side wall of the first articulation through the hollow shaft part to the second articulation.
 27. The articulated operating arm as claimed in claim 25, wherein the at least one conduit is attached to the first articulation and to the second articulation close to the first axis), and/or wherein the at least one conduit is attached against a side wall of the second articulation.
 28. (canceled)
 29. (canceled)
 30. (canceled)
 31. (canceled)
 32. (canceled)
 33. (canceled)
 34. The articulated operating arm as claimed in claim 25, wherein the at least two articulations comprise a third articulation, and that the second articulation is connected for pivoting around a third axis to the third articulation, and that a further control member is provided for the purpose of moving the third articulation relative to the second articulation, wherein the further control member is connected for pivoting around a fourth axis to the second articulation, this fourth axis being parallel to the third axis. 